– Copied from customer query –
Hello,
The GigaBlox SFP looks like an excellent product, but the datasheet has no text describing the maximum transmission distance. One of the arrows on the diagram on page 5 is labelled “1000BASE-LX, 10 km Fiber”. This suggests the maximum transmission distance maybe 10 km, but I’d like to confirm this.
I plan to use a GigaBlox SFP to send data from an ROV-mounted IP camera up a 6 km umbilical cord. However, this system involves optical slip rings which may add additional attenuation, especially if they are not in perfect condition. I would prefer to use the GigaBlox with a 20 km SFP module to ensure a nice strong signal.
I am considering using a Trendnet TEG-MGBS20 (20 km) SFP module. Can you confirm if the GigaBlox SFP will be compatible? Or would it be limited to 10km SFP module?
I’ve attached a data sheets for the Botblox board (see page 5) and Trendnet SFP module.
Thanks you very much for your help!
The GigaBlox SFP board itself does not impose any limit on the optical transmission distance. The achievable range is determined entirely by the SFP module and the fiber link budget.
The “1000BASE-LX, 10 km Fiber” label in the diagram on page 5 is simply an example corresponding to a typical LX SFP module. If you use a longer-reach SFP module (for example a 20 km LX module), the system should operate at that distance provided the overall optical link budget is sufficient.
In general, the GigaBlox SFP is compatible with standard MSA-compliant 1G SFP modules, so a module such as the Trendnet TEG-MGBS20 should work.
For your ROV application, the main factor to check will be the total optical loss in the system. A 6 km fiber run plus the additional attenuation from optical slip rings could consume a significant portion of the link budget, so using a 20 km rated SFP is a sensible approach to provide margin.
If helpful, feel free to share the fiber type and any estimated slip-ring loss and we can sanity-check the expected link budget.